The present invention generally relates to direction-sensitive hearing aid with a housing, at least one signal processing means, at least one microphone in communication with the signal processing means as well as at least one sound opening.
German Patent No. DE-AS 23 37 078 discloses a direction-sensitive hearing aid with a directional microphone that is arranged in a housing and has two spatially separated sound admissions that are acoustically connected to spatially separated sound openings for the admission of the sound into the hearing aid. The directional microphone recognizes the direction of the sound signal based on the difference in running time of sound waves incident onto the sound admissions of the directional microphone. This known hearing aid, accordingly, requires the use of directional microphones.
European Patent No. EP 0 499 699 B1 discloses a hearing aid device with two microphones wherein each microphone has its own sound admission opening allocated to it, and the direction of a sound wave can be identified by determining the difference in running time of the entering sound waves. Given this hearing aid device, the sound admission openings are arranged at the upper side. As a result, these openings easily get dirty and also limit the possibilities with respect to design and operating ease due to their positioning. In addition, this hearing aid device is difficult to shield against electromagnetic noise fields, for example, to radiotelephones, as a result of the sound admission openings to be arranged in the operating region.